1. Field of the Invention
The present invention relates to a semiconductor device having densely packaged semiconductor chips, in particular of the same size.
2. Background Art
FIG. 21 is a sectional view showing a structure of a conventional semiconductor device having stacked semiconductor chips.
A conventional method for the high-density packaging of semiconductor chips will be described below. First, on a substrate 10q provided with conductive layers 10p, the largest chip 1p among semiconductor chips to be packaged is die-bonded with on-the-chip electrodes facing up. Similarly, a semiconductor chip 1q smaller than the semiconductor chip 1p previously bonded is die-bonded on the semiconductor chip 1p. However, the semiconductor chip to be die-bonded on the underlying semiconductor chip must always be die-bonded on the space where there are no electrodes of the underlying semiconductor chip. Next, the electrodes of each of thus stacked semiconductor chips 1p and 1q are electrically connected to conductive layers 10p on the substrate 10q using wire bonding.
However, when semiconductor chips of the same size are densely mounted by a conventional method, the electrodes of an underlying semiconductor chip are always hidden by the die-bonded overlying semiconductor chip, and cannot be electrically connected to conductive layers on the substrate.